Power regulators are commonly used to provide a stable power supply voltage independent of load impedance, input voltage variations, temperature, and time. A low-dropout (LDO) regulator is a type of voltage regulator that can provide a low dropout voltage, i.e., a small input-to-output differential voltage, thus allowing the LDO regulator to maintain regulation with small differences between input voltage and output voltage. LDO regulators are used in a variety of applications (e.g., providing an on-chip power supply, etc.).
A charge pump is a type of DC-to-DC converter that uses capacitors as energy-storage elements to create a power source. Charge pumps are used in a variety of applications (e.g., providing an on-chip power supply that supplies power from a limited external power supply, etc.).